Earlier this year, Veljekset Paupek, based in Tornio, Finland, leased a Metso Lokotrack LT200HP cone crusher from Rotarent to accompany their own Lokotrack LT106 jaw crushing plant to create a two-stage crushing process.
"We were able to crush the entire batch of 10,000 tonnes in just over two weeks. We were positively surprised both by the operating speed and the impressive performance in crushing asphalt of the combination of cone crusher and jaw crushing plant," says Ville Takalo, Paupek's technical manager, when assessing the job.
The asphalt was collected from a 600-hectare site at the Outokumpu steel plant in Tornio. With grain sizes of 0–32 mm, the final crushed product will be compressed and reused in maintaining the roads at the plant site.
Brothers Petri and Tero Karjalainen from Paupek's subcontractor P&T Karjalainen operated the Metso Lokotracks at the Tornio steel plant. The work was done under variable winter weather conditions, with the temperature ranging from 5 °C to -10 °C.
The lowest part of the asphalt pile had to be loosened with a frost spike before the asphalt could be fed into the jaw crusher. The jaw crusher was set for a grain size range of 38–50mm, with the LT200HP set at 25mm.
"We hadn't used this kind of cone crusher before, but we were able to learn the operation well. Having instructions in Finnish for the machine's Metso IC™ process control helped a lot," says Petri.
The crushing mainly took place during daylight hours in the short winter days, and the brothers were able to crush over a thousand tons every day.
"With the speed at which the Lokotracks can chew up the asphalt, it's not impossible for this combination to get through 2,000 tons a day," Petri believes.
Asphalt is not a hugely demanding material for jaw and cone crushers that have been designed for hard rocks. At the Tornio site, the jaw crusher is said to have consumed 10 litres of fuel every hour, and the cone crusher 20 litres. One tank of fuel was said to be enough for two days of heavy crushing.
The conveyor of the LT200HP was said to supply asphalt at such a healthy rate that Petri was kept busy feeding the conveyer nearly all the time. The fine-grained asphalt was placed in piles behind a knoll approximately 50 meters away, to be used later.
After the asphalt contract was completed, the jaw crusher continued working at the Tornio steel plant, chewing its way through a frozen pile of concrete that had been processed with pulverising shears.
Paupek purchased its own LT106 jaw crusher from Metso in 2017. The machine is mainly used at the company's recycling yard in Oulu, where the company crushes 25,000–30,000 tonnes of recycled concrete and bricks every year.
"We can still use the crusher for odd jobs, such as the contract in Tornio and a previous one in Rovaniemi. The LT106 is easy to transport on a trailer when needed," explains Ville Takalo from Paupek.
He added: "Once the concrete has been crushed and the rebar removed, it is sold to be used as road filler and artificial fill, for example. Sites that have used the crushed concrete include a recycling yard and a new shooting range in Liminka. Demand has remained steady."
"When crushing recycled materials, it's important to achieve production levels that are high enough to keep everything profitable.
"Metso's Lokotrack jaw crusher has proved to be a reliable machine that can quickly be warmed up for use in our cold northern conditions."